Converter process.



UNITED STATES PATENT OFFICE.

OTTO THIEL, 0F LANDSTUHL, GERMANY.

CONVERTER PROCESS.

No Drawing.

To all whom it may concern:

Be it known that I, O'r'ro of Landstuhl, country of the RhenishPalatinate, Empire of Germany, have invented certain new and usefulImprovements in or Relating to Converter Processes, of which thefollowing is a specification.

This invention relates to an improved converter process.

The objects and advantages of the invention will be described in thefollowing specification and be defined by the following claims.

The process according to the present invention is characterized by thefact that the charge of pig metal to be treated is not placed in theconverter at once but in two or more parts, the further part or parts ofthe charge being added at the end of the blast of the first part of thecharge or at the end of the supplementary blast, in the case ofphosphoric pig, whereupon the complete charge is subjected to the blastto the end and finished, not in a separate furnace, but in the sameconverter.

An example will best explain the process in question. In a convertercharge of 15 tons, the ordinary blast period is generally 1315 minutes,the preliminary blast 11-12 minutes and the supplementary blast 2-3minutes.

In the experimental charge, at first 12 tons were poured into theconverter. The preliminary blast lasted 7 minutes, the supplementaryblast 1m. 15s. and the converter was then tipped over. An analysis ofthe slag showed 11.44% of iron and 20.24:% of P 0 The rest of thecharge, about three tons, was then poured into the converter. A distinctreaction took place. The converter was turned up, and the blast turnedon for another 2m. 5s. An analysis of the slag showed 8.16% of iron,23.16% of P 0 that is to say 3.28% of iron less. The total time ofblowing amounted to 10m. 20s., that is to say, 3 minutes less than inordinary charges. The greater portion of the charge is, therefore,subjected to the blast for a period according to the judgment of theoperator, and then the rest added, whereupon the blast is turned on tothe combined charge to the end.

Obviously the process is subject to various modifications depending onthe quantity of the additional ig iron and on the moment at which theaddition is made.

By reducing the percentage of iron in the THIEL, engineer,

Specification of Letters Patent.

Patented Dec. 9, 1913.

Application filed August 4, 1910. Serial No. 575,481.

slag, the waste is reduced. This waste can be still further reduced if,after the blast has been applied to the first portion of the charge,iron ores are introduced into the converter. The addition of iron oresin itself is known, but it was of course only very small, as by far thegreatest quantity of the impurities was already removed from the ironbath at the moment in question. In the present process, the addition ofore can be made much greater, owing to the subsequent addition of pigiron, but naturally only in as far as the heat conditions admit it. Suchan addition of ore considerably reduced the time of the blast. Additionsof pig iron to completely blown charges are well known. They are usedfor deoxidation, recarbonizing, and higher carbonizing. As long as thereis a question of additions after the blowing of the charge is completed,such additions cannot be considered as parts of the charge. The partcharges according to the present invention however are not identicalwith such additions. They form parts of one and the same charge whichare subjected to the blast as a complete whole until completion. Thesize of the complete charge depends on the construction of theconverter, the power of the blower, etc, so that one speaks of a 10, 15,20, 25 tons converter, etc.

The advantages of the new process are as follows: (1) Reduction of thetime of blowing by 20-30% and therefore a smaller engine power andsmaller consumption of material for getting the converter ready; (2)less waste; (3) larger yield of phosphoric acid in the Thomas slag. Itis well known that in hot blast charges a considerable perccntagc of thephosphoric acid formed, is volatilized. This is avoided in the presentcase; (4) better quality; (5) possibility of using greater charges; (6)possibility of using greater additions of iron ores in hotblast charges,for, if ore is added at the end of the blowing, a large quantity ofimpurities still remains.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

1. A converter process which consists in introducing a portion of thepig metal into the converter, then subjecting the charge to the blastand allowing it to remain in the converter, then introducing more of thecharge into the converter and then subjecting the combined charge to theblast to the end, until finished.

2. A converter process which consists in introducing a portion of thepig metal into the converter, then subjecting the charge to the blastand allowing it to remain in the converter, then introducing theremainder of the charge into the converter and then Subjecting thecombined charge to the blast to the end, until finished.

3. A converter process which consists in introducing a portion of thepig metal into the converter, then subjecting the charge to I the blastand allowing it to remain in the converter, then introducing a portionof the remainder of the charge into the converter and then subjectingthe combined charge to the blast, then introducing more of the chargeinto the converter, and subjecting the combined charge to the blast tothe end, unt l finished.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

OTTO THIEL.

Witnesses:

ERNEST L. Ivns, MELANIE MANG.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

